[REVIEWED-86] Constraint 6 amended — steward placed; executor verification

The steward placed the amendment. Recording the verification promised, and the
instrument limit it exposed.

Bounded-diff proof: 9 insertions, 0 deletions. Constraint 6's original text
byte-identical at 222 chars. Zero pre-amendment lines missing. Purely additive,
as designed -- the caution is refined, not relaxed.

Both jurist conditions verified present verbatim in the placed text: the Q2 weld
(fail to coincide, not cancel; never cited as assurance something was caught) and
the Q3 self-limiting clause (jurist and executor share formation; neither the
doctrine nor its evidence establishes that pair as a check in the strong sense).
6/6 contained, 5/5 controls absent, instrument verified.

List integrity confirmed with pandoc rather than by reasoning about it: the
doctrine parses INSIDE list item 6 despite the double blank line. No structural
problem.

The verification took three attempts, and the first two failures were mine. Both
controls I built for the Q3 negation were substrings of the sentence that does
the negating -- "establishes that the pair constitutes a check" appears verbatim
inside "Neither this doctrine nor any evidence ... establishes that the pair
constitutes a check". They leaked by construction. The instrument was right to
refuse certification twice; the controls were malformed.

That is a real limit and it is now documented in the script: substring containment
has no notion of polarity and CANNOT verify a negation. Controls must be built by
inversion, never by extraction. Where polarity is what matters the instrument does
not settle it -- read the sentence, and report that containment did not cover it.
Which is the case here: that the Q3 clause denies rather than affirms was
established by reading, not by the check.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WuMjg3ipEVa3n8CoSzoyvc

claude/governance/check_containment.py

@@ -14,6 +14,24 @@ Every run carries POSITIVE CONTROLS: near-miss strings that must be absent. If a
 is found, the instrument is not discriminating and its passes mean nothing. An absence
 is not evidence until the instrument is shown capable of detecting presence.
 
+KNOWN LIMIT — THIS INSTRUMENT CANNOT VERIFY A NEGATION.
+    It tests whether an exact string is present. It has no notion of polarity. So a
+    sentence of the form "X does NOT hold" contains, as a literal substring, the
+    affirmative "X holds" — and any control built from that affirmative will leak by
+    construction, every time, no matter how correct the text is.
+
+    Hit twice within five minutes on 2026-08-02 while verifying the Constraint 6
+    placement: both attempts to control for "the doctrine must not claim the
+    jurist-executor pair IS a check" used substrings of the very sentence that denies
+    it. The instrument was right to refuse certification both times; the controls were
+    malformed.
+
+    Build controls by INVERSION, not by extraction — a string that would appear only if
+    the meaning were flipped ("the jurist and the executor differ from each other in
+    formation", dropping the "do not"), never a fragment lifted out of the sentence
+    under test. And where polarity is what matters, this instrument does not settle it:
+    read the sentence. Report that you read it, and that containment did not cover it.
+
 USAGE
     ./check_containment.py manifest.json